Lawnmower protective guard

ABSTRACT

Lawnmower having a guard extending across lower portion of discharge opening and embodying vertical flange outwardly of and in alignment with tip of rotary cutter blade and horizontal flange extending inwardly from upper edge of vertical flange over and in spaced relation to tip of cutter blade. Rear end of guard extends beyond trailing edge of discharge opening and forward end of guard extends forward from leading edge of discharge opening a distance equal substantially the distance from said leading edge to first tangent of exposure of cutter blade less the height of horizontal flange above cutter blade.

United States Patent Grimes 1 Mar. 7, 1972 [54] LAWNMOWER PROTECTIVEGUARD 2,864,226 12/1958 Bright ..56/l3.4 [72] Inventor: John J. Grimes,Route 4, Box 554A, Sel- Primary Emminer RusseR Kinsey 3670]Attorney-Jennings, Carter & Thompson [22] Filed: Aug. 12, 1970 [57]ABSTRACT [21] Appl. No.: 63,176

Lawnmower having a guard extending across lower portion of dischargeopening and embodying vertical flange outwardly of [52] US. Cl...56/320.2 and in alignment with tip of rotary cutter blade andhorizontal [51] Int. Cl. ..A0ld 35/26 flange extending inwardly fromupper edge of vertical flange [58] Field of Search ..56/320.2, 12.2,13.4 Over and in Spaced relation to p of cutter blade. r end f guardextends beyond trailing edge of discharge opening and [56] ReferencesCited forward end of guard extends forward from leading edge ofdischarge opening a distance equal substantially the distance UNITEDSTATES PATENTS from said leading edge to first tangent of exposure ofcutter blade less the height of horizontal flange above cutter blade.3,468,108 9/l969 Mattson ..56/l3.4 2,719,396 10/1 955 Morris et al...56/l 2.2 4 Claims, 5 Drawing Figures PATENTEDMAR 7. I972 I NVEN TOR.John I Grimes W MfW Attorneys LAWNMOWER PROTECTIVE GUARD BACKGROUND OFTHE INVENTION This invention relates to a lawnmower having a protectiveguard and more particularly to a guard member which is secured to thehousing for a rotary cutter blade and extends transversely across thelower portion of the discharge opening for the housing.

As is well known in the art to which my invention relates, difficultieshave been encountered in protecting persons against injury from contactwith the rotary blade and from flying debris discharged from rotarylawnmowers, such as bits of metals, rocks and the like. While manysafety devices have been proposed for rotary lawnmowers, such deviceshave not reduced the exposure of the tip of the rotary blade to zero asthe blade rotates relative to the discharge opening.

BRIEF SUMMARY OF THE INVENTION In accordance with my invention, Iprovide a guard member which is secured to and extends transverselyacross the lower portion of the discharge opening of a rotary lawnmower.The guard member is provided with a vertical flange which extends acrossthe discharge opening with an intermediate portion of the verticalflange being in horizontal alignment with the path of rotation of thecutter blade. An inwardly extending, horizontal flange is carried by theupper edge of the vertical flange and extends over and in spacedrelation to the path of rotation of the tip of the cutter blade. Therear end of the horizontal flange extends beyond the trailing edge ofthe discharge opening while the forward end of the horizontal flangeextends forwardly from the leading edge of the discharge opening adistance equal substantially the distance from the leading edge to thefirst tangent of exposure passing through the upper portion of theleading edge and the path of rotation of the tip of the cutter bladeless the height of the horizontal flange above the cutter blade.

Apparatus embodying features of my invention is illustrated in theaccompanying drawing, forming a part of this application in which:

FIG. 1 is a side elevational view, partly broken away, showing alawnmower having my improved guard member mounted thereon;

FIG. 2 is a top plan view of the lawnmower shown in FIG. 1;

FIG. 3 is an enlarged, sectional view taken generally along the line 33of FIG. 1;

FIG. 4 is a fragmental, sectional view taken generally along the line4-4 of FIG. 3; and

FIG. 5 is a diagrammatic view taken generally along the line 55 of FIG.3 showing the relationship of the cutter blade to the elongated guardmember.

Referring now to the drawing for a better understanding of my invention,I show a lawnmower having a downwardly opening housing which is mountedon supporting wheels 11. The mower is provided with a conventional-typepower unit, such as an internal combustion engine 12. Upwardly andrearwardly extending handle members 13 are mounted at the rear end ofthe mower, as shown in FIGS. 1 and 2.

As shown in FIGS. 1, 2 and 3, the downwardly opening housing 10 isprovided with a tangential discharge opening 14 at one side thereof fordischarging grass cuttings outwardly and laterally of the housing 10 ina manner well understood in the art to which my invention relates. Thepower unit 12 is provided with a vertical drive shaft 16, as shown inFIG. 1. Secured to and adapted for rotation with the shaft 16 is arotary cutter blade 17 having a cutter edge 18 adjacent each endthereof. The tip of the cutter blade 17 rotates in a circular pathindicated by the dot-dash line 19. The rotary cutter blade 17 thusrotates in a horizontal plane with the tip thereof moving in an arcuatepath inwardly of the inner surface of the downwardly opening housing 10.

My improved guard member is indicated generally at 21 and comprises avertical flange 22 which extends transversely across the lower portionof the discharge opening 14. Secured to and extending inwardly of theupper edge of the vertical flange 22 is a horizontal flange 23 having anarcuate, concave inner edge 24. Preferably, the horizontal flange 23 isformed integrally with the vertical flange 22, as shown in FIG. 4. Thevertical flange 22 of the guard member 21 is positioned outwardly of thepath of rotation of the tip of the cutter blade 17 with an intermediateportion of the flange 22 being in horizontal alignment with the path ofrotation 19 of the tip of the cutter blade 17. Also, as shown in FIG. 4,the horizontal flange 23 extends inwardly over and in spaced relation tothe path of rotation 19 of the tip of the cutter blade 17.

The rear end of the horizontal flange 23 extends rearwardly beyond thetrailing edge 26 of the discharge opening 14, as shown in FIG. 3. Theforward end of the horizontal flange 23 extends forwardly from theleading edge 27 of the discharge opening 14 a distance equalsubstantially to the distance from the leading edge 27 to the firsttangent or exposure defined by a line which passes through the upperportion of the leading edge 27 and extends forward tangent to the pathof rotation 19 of the tip of the cutter blade less the height of thehorizontal flange 23 above the tip of the cutter blade 17 and its pathof rotation 19. The first tangent of exposure is thus indicated by theline 28 in FIGS. 3 and 5 and extends from the upper inner surface of thedischarge opening 14 adjacent the edge 27 thereof and extends tangent tothe path of rotation 19 of the tip of the cutter blade 17. Since thecutter blade 17 is below the horizontal flange 23, as indicated by line29 in FIG. 5 and as clearly shown in FIG. 4, the horizontal flange 23does not have to extend the full length from the edge 27 to the point offirst tangent of exposure, as indicated at 25. That is, the distance thehorizontal flange 23 extends forward is reduced by an amount equal theheight that the horizontal flange 23 is above the path of rotation ofthe tip of the cutter blade 17.

The last tangent of exposure is indicated by the line 31 which passesthrough the trailing edge 26 of the discharge opening 14 and extendsforward tangent to the path of rotation 19 of the tip of the cutterblade 17. As shown in FIG. 3, the rear end of the horizontal flange 23extends rearwardly past the trailing edge 26. Accordingly, the exposureof the tip of the rotary cutter blade 17 is zero at the first tangent ofexposure, indicated at the point line 28 touches the path of rotation19, and remains so throughout the last tangent of exposure, indicated atthe point line 31 touches the path of rotation 19. The guard member 21thus provides complete protection throughout the critical areas ofconcern in safety specifications for rotary power mowers.

As shown in FIG. 3, the forward inner portion of the horizontal flange23 is convexly curved to present a rounded leading edge 32 to thusprovide a minimum resistance to the outwardly moving stream of grasscuttings. As shown in FIGS. 3 and 4, depending, vertical flanges 33 arecarried by the forward and rear ends of the horizontal flange 23 witheach depending flange 33 being secured rigidly to the housing 10 of thelawnmower by suitable means, such as by welding. Accordingly, theelongated guard member 21 not only provides a safety device for thelawnmower but also adds strength thereto.

From the foregoing description, the construction and opera tion of myimproved lawnmower protective guard will be readily-understood. Thedepending flanges 33 are secured rigidly to the inner surface of thehousing 10 at opposite sides of the discharge opening 14 with thevertical flange 22 extending transversely of the lower portion of thedischarge opening 14. As shown in FIG. 4, an intermediate portion of thevertical flange 22 is in horizontal alignment with the path of rotationof the tip of the cutter blade 17 whereby a foot or hand ofa personcannot move horizontally into contact with the blade 17 and any debristhrown outwardly of the end of the blade 17 strikes the vertical flange22. The horizontal flange 23 is positionecl at an elevation above andextends over the tip of the cutter blade 17, as shown in FIGS. 3 and 4.With the guard member 21 thus mounted, the rear end of the horizontalflange 23 extends rearwardly of the trailing edge 26 while the forwardend of the horizontal flange 23 extends from the leading edge 27 of thedischarge opening 14 a distance equal sub stantially the distance fromthe leading edge 27 to the first tangent of exposure passing through theupper portion of the leading edge 27 and the path of rotation 19 of thetip of the cutter blade 17, less the height of the flange 23 above thecutter blade 17. Accordingly, the horizontal flange 23 extends from theleading edge 27 of the discharge opening 14 to a point 30 on the line29, as shown in FIG. 5, which represents the distance from the leadingedge 27 to the point of the first tangent of exposure 25 less the heightof the horizontal flange 23 above the cutter blade 17.

From the foregoing, it will be seen that l have devised an improvedlawnmower protective guard. By providing a protective guard whichreduces the blade tip exposure at the first tangent to zero andmaintains the blade tip exposure at zero through the last tangent, mysafety guard member complies with safety specifications for rotary powermowers in the most critical areas of concern. Furthermore, by providingthe vertical flange 22 and the horizontal flange 23 which extends to thepoints mentioned hereinabove, I reduce to a minimum the danger of a handor foot of a person contacting the rotary tip of the blade.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications without departing from thespirit thereof.

What I claim is:

1. In a lawnmower having a downwardly opening housing with a dischargeopening at one side thereof and a cutter blade mounted for rotation in ahorizontal plane inwardly of said discharge opening:

a. an elongated guard member having a vertical flange extendingtransversely across the lower portion of said discharge openingoutwardly of the path of rotation of the tip of said cutter blade withan intermediate portion of said vertical flange being in horizontalalignment with said path of rotation of the tip of said cutter blade,

b. a horizontal flange carried by the upper edge of said verti calflange extending inwardly over and in spaced relation to said path ofrotation of the tip of said cutter blade,

. the rear end of said horizontal flange extending inwardly over saidpath of rotation and rearwardly beyond the trailing edge of saiddischarge opening, and

d. the forward end of said horizontal flange extending inwardly oversaid path of rotation and forwardly from the leading edge of thedischarge opening a distance equal substantially to the distance fromthe leading edge of said discharge opening to a first tangent ofexposure defined by a line passing through the upper portion of saidleading edge and extending forwardly and tangent to said path ofrotation of the tip of said cutter blade less the height of saidhorizontal flange above said path of rotation of the tip of said cutterblade.

2'. A lawnmower as defined in claim 1 in which the central portion ofthe inner edge of said horizontal flange is concavely curved.

3. A lawnmower as defined in claim I in which the forward inner portionof said horizontal flange is convexly curved to present a roundedleading edge.

4. A lawnmower as defined in claim 1 in which a depending flange iscarried by said forward end and rear end of said horizontal flange witheach said depending flange being secured rigidly to said housing for thelawnmower.

1. In a lawnmower having a downwardly opening housing with a discharge opening at one side thereof and a cutter blade mounted for rotation in a horizontal plane inwardly of said discharge opening: a. an elongated guard member having a vertical flange extending transversely across the lower portion of said discharge opening outwardly of the path of rotation of the tip of said cutter blade with an intermediate portion of said vertical flange being in horizontal alignment with said path of rotation of the tip of said cutter blade, b. a horizontal flange carried by the upper edge of said vertical flange extending inwardly over and in spaced relation to said path of rotation of the tip of said cutter blade, c. the rear end of said horizontal flange extending inwardly over said path of rotation and rearwardly beyond the trailing edge of said discharge opening, and d. the forward end of said horizontal flange extending inwardly over said path of rotation and forwardly from the leading edge of the discharge opening a distance equal substantially to the distance from the leadiNg edge of said discharge opening to a first tangent of exposure defined by a line passing through the upper portion of said leading edge and extending forwardly and tangent to said path of rotation of the tip of said cutter blade less the height of said horizontal flange above said path of rotation of the tip of said cutter blade.
 2. A lawnmower as defined in claim 1 in which the central portion of the inner edge of said horizontal flange is concavely curved.
 3. A lawnmower as defined in claim 1 in which the forward inner portion of said horizontal flange is convexly curved to present a rounded leading edge.
 4. A lawnmower as defined in claim 1 in which a depending flange is carried by said forward end and rear end of said horizontal flange with each said depending flange being secured rigidly to said housing for the lawnmower. 